All organisms are grouped into five kingdoms. Those are Monera, Protoctista, Fungi, Plantae and Animalia. The division is made based on 3 criteria. Those are cellular organization, arrangement of cells, and type of nutrition. Cellular organization is whether they are eukaryotic or prokaryotic. Cell arrangement is whether they are unicellular, multicellular, with or without true tissue differentiation etc. Type of nutrition is whether they are autotrophic or heterotrophic. Kingdom Protoctista includes algae, protozoans, oomycota and slime moulds.
An adaptation that makes bipedalism possible is the need to get around. If your slithering on the ground, you could get diseases, or get hurt.
Before assessing the two given cases, an assumption needs to be made about the digestion of the two types of food items, corn and beef. Let us assume that both get digested by expending same amount of energy by the human body. Let the amount of energy at producer level be an arbitrary X.
Case 1: Corn to human:
Since corn is at the producer level, it will have X amount of energy. The transfer of energy from corn to human will take place with a loss of 90% energy at the producer level. Hence the humans will receive 10% of X amount of energy.
Case 2: Corn to cow to human:
Since corn has X amount of energy, only 10% will pass to the next level, i.e. cow. So cow has 10% of X. Cow transfers only 10% of the energy that it has. Hence humans receive only 10% of 10% of X amount of energy.
It can be seen that humans receive more energy in case 1 than case 2. Hence we can say that it is more efficient for humans to feed on corn.
I think it is from the Paleozoic era
Hope this helps
Atmospheric nitrogen fixation<span> is the process in which lightning converts </span>nitrogen<span>gas in the </span>atmosphere<span> into usable compounds. It makes </span>nitrogen<span> available to</span>organisms<span>.</span>
